Unit 1_Spinal Cord & Meninges Flashcards
Describe the spinal cord.
Major reflex center and conduction pathway between the body and brain.
Begins at the foramen magnum as continuation of the medulla oblongata.
Ends at L1/L2 in adults (42-45cm), L3/L4 in children.
How many pairs of spinal nerves do we have?
31
Cervical - 8 (7 vertebrae)
Thoracic - 12 (12 vertebrae)
Lumbar - 5 (5 vertebrae)
Sacral - 5 (5 vertebrae)
Coccygeal - 1 (4 vertebrae)
Where does the spinal nerve exit in C1?
C1 spinal nerve exits above C1 vertebrae
Where does the spinal nerve exit in C7?
C8 spinal nerve exits below C7 vertebrae/above T1
Why is the cervical spine called the cervical enlargement?
The nerve that innervates the diaphragm (C3-C5), keeping us alive is here.
Nerve cell bodies that go on to develop the upper limbs are here (C4-C7).
What is the lumbosacral enlargement?
The nerve cell bodies that go on to form the fibers, neurons, nerves innervating the buttox down, abdominal muscles, lower limbs live here.
What is the conus medularis?
Found at L1-L2, it’s a tapering/cone of the spinal cord.
What is the cauda equina?
Nerve roots that look like a horse’s tail from where the cord stopped at L1-L2 to where they need to go.
What is filum terminale (terminal filament)?
Extension off the cord, continue down through the sacral canal and bind down on the sacrum and coccyx.
What is the dural sac (dura mater)?
Sac follows, meninges follow, surround the brain all the way down into the spinal cord, the sac holds the cerebrospinal fluid (CSF), protection for the spinal cord, encloses the CSF around S2.
What is cauda equina syndrome?
It’s a catch all, bundle of nerve roots that are going to exit right/left side of body, there’s been some sort of damage, which may just be compression from the intervertebral disc pushing on nerve roots.
What nerve rootlets support motor?
Anterior/Ventral
What nerve rootlets support sensory?
Posterior/Dorsal
What nerve structure comes off of the spinal cord itself?
Anterior/Posterior nerve rootlets
When nerve rootlets join together, what do they form?
Anterior/Posterior Root
What is a bulge that forms on the posterior nerve roots made up of a density of cell bodies affecting general sensation?
Ganglion
When the anterior and posterior nerve roots join together, what do they form?
Spinal nerve
When the spinal nerve is formed and bifurcates, what does it form?
Posterior ramus and anterior ramus
Become mixed nerves to support motor and sensory function
What is derived from within the spinal cord?
The nerve rootlets and fibers
What is a branching network of intersecting nerves that form nerve plexuses in the cervical spine, lumbar spine, sacral spine?
Ventral Primary Rami
What is a situation when an area of skin which is innervated by fibers off the dorsal root of a single spinal nerve forms a mapping pattern of sensory information?
Dermatomes
What is connective tissue membranes that surround and support the spinal cord and the nerve roots, as well as contain cerebrospinal fluid (CSF)?
Meninges
What are meninges composed of?
3 layers:
Dura mater (superficial)
Arachnoid mater
Pia mater (deep)
What is a superficial space to the dura mater of the spinal meninges?
Epidural space (fat)
What is between the arachnoid and pia mater within the spinal meninges?
Subarachnoid space
Where the cerebrospinal fluid flows
What is the deepest layer of the spinal meningeal layers that adheres to the spinal cord, continues as the filum terminale and forms denticulate ligaments that bind the cord down laterally to the dura mater?
Pia mater
What occurs during spinal anesthesia?
Poke a needle into lumbar epidural fat and bathe the cord with anesthesia
What occurs during lumbar puncture CSF?
Retrieve and test cerebrospinal fluid, for ‘itis’ meningitis, can poke a needle distal to L1-L2 (below spinal cord)
What is one of the main branches of the subclavian artery?
Vertebral artery (2)
Heads into the transverse foramen at C6, and goes through every cervical vertebrae and then branches off of it to feed the posterior aspect of the spinal cord to form 1 posterior spinal artery.
What is the function of the anterior vertebral artery?
1 vertebral artery that runs down the midline of the anterior spinal cord made up of a fusion of the two vertebral artery branches to provide blood supply
Where are a collection of veins housed?
In the epidural space, outside the dura housed within the neural arch of the vertebral column, there’s a plexus of veins draining the cord in the fat.
